1. Field of the Invention
This invention pertains to a small pipe cutting device adapted for use in restricted or confined spaces. More particularly, the subject invention relates to a pipe cutting device which automatically advances the cutting tool in response to ratchet-like movement of the device.
2. Prior Art
A variety of pipe cutting devices have been developed over the years having configurations which appear to be generally adapted for use in cutting small pipe in confined areas. Such small pipe would generally be described as pipe having a diameter of an inch and a half or less, and more often in a range of one-half inch to one inch in diameter. Illustrative of such piping is the copper tubing which is utilized in plumbing systems and related fluid and gas transmission lines. In making repairs on broken pipe or performing other work which requires cutting an existing pipe in place, the available work space for rotating a cutting tool around a pipe is frequently limited. For example, the copper tubing within a residence is typically run between floor joists and may often be anchored in hard-to-reach positions. Frequently, repair work must be conducted through a small opening in a floor or ceiling and on a pipe which may permit only ten to twenty degrees of rotational movement with respect to the cutting tool.
A number of mechanical configurations have been developed to meet some of the difficulty encountered under such circumstances and are illustrated by the following patents: U.S. Pat. Nos. 4,157,615 and 4,177,557 of Courty; U.S. Pat. No. 2,769,235 by Martois, U.S. Pat. Nos. 2,447,371 and 3,715,804 by Kelly and U.S. Pat. No. 882,432 by Thomas. Although these various devices provide the means for applying a cutting force at the exterior perimeter of the tube, the various structures illustrated fail to provide automatic adjustment of this cutting surface in a manner which provides maximum stability of the cutting tool as it is driven around the pipe exterior. Instead, the prior art devices are subject to premature release of the pipe, uncontrolled deviation from the proper planar cutting path and similar problems which arise from the inability of the tool to be retained in firm, stable contact with the cutting edge and clamped pipe in proper orientation.